High blood pressure is often called “the silent killer” because it may show no symptoms, making it all the more important to know your blood pressure numbers – and to check them regularly. Photo / Getty Images
High blood pressure is often called “the silent killer” because it may show no symptoms, making it all the more important to know your blood pressure numbers – and to check them regularly. Photo / Getty Images
High blood pressure affects one in five NZ adults and is a major cause of heart attacks and strokes.
Experts recommend medication, reducing salt intake, and regular exercise to effectively lower blood pressure.
Monitoring blood pressure at home can help track changes and motivate healthy lifestyle adjustments.
It’s the thing we dread hearing at our midlife health check, but in fact an early diagnosis could prove a blessing. High blood pressure affects one in three UK adults, accounting for more than half of all heart attacks and strokes [one in five NZ adults]. It’s oftencalled “the silent killer” because it may show no symptoms, making it all the more important to know your blood pressure numbers – and to check them regularly.
“Most people in the UK have blood pressure that’s higher than the ideal, but as a general guide, normal blood pressure is considered to be between 90/60mmHg and 120/80mmHg,” says Graham MacGregor, a professor of cardiovascular medicine and the chairman of Blood Pressure UK.
Why stress isn’t the problem
It’s not uncommon to hear someone attributing high blood pressure to stress. In truth, stress itself is unlikely to be the cause or the answer. “If I pointed a machine gun at you, your blood pressure would go up, but the question is does stress cause a long-term rise in blood pressure? The evidence just isn’t there,” says MacGregor. Stress only becomes a factor if it leads to an unhealthy lifestyle – like eating badly, smoking, drinking and losing sleep.
So what are the proven ways of reducing blood pressure? The best methods to reduce blood pressure, according to the experts, are:
1. Medication
Fortunately, we have very effective ways of reducing blood pressure with four main types of medicine. “They reduce blood pressure through different mechanisms and that’s important because your body will try to stop it working,” says MacGregor. “One tablet might reduce the pressure through one mechanism, and then if your body manages to block it, you might be prescribed another pill that works through a different mechanism. If you’re given two tablets that work in different ways, that’s more effective than one, and if you’re on three, that can be more effective than two.”
Medication can help to manage high blood pressure. Photo / 123rf
The four main types are: Ace (angiotensin-converting enzyme) inhibitors and angiotensin receptor blockers (ARBs), which both work by controlling the hormones that help relax and widen the blood vessels, which in turn lowers the pressure; thiazide diuretics remove excess fluid from the body; and calcium-channel blockers (CCBs) prevent calcium from entering the cells of the heart and arteries (since calcium causes them to contract more strongly), allowing blood vessels to relax and open.
Side effects for some include dizziness and headaches. “Some people won’t have any side effects. It depends on the drug and the person, and also whether they are on any other medicines,” says Ruth Goss, a senior cardiac nurse with the British Heart Foundation. “The long-term health consequences of uncontrolled high blood pressure are much worse. If you have any concerns about your medication, don’t alter the dose or stop taking it. Talk to your GP.”
2. Cut back on salt
This is absolutely key – the more salt you eat, the higher your blood pressure will be. Even if you are on blood pressure medication, a salty diet can make it work less effectively. Reducing your salt intake will have an impact quickly too – often within weeks.
Though we need a small amount of salt to stay healthy – about 4g each day – we should eat no more than 6g, or one level teaspoon. Most of us eat too much. Roughly 75% is from processed foods, 15% is added during cooking or before eating (so remove the salt cellar from the table), and 10% is found naturally in food.
Check labels carefully for salt or sodium, and be aware of high-salt items, like tomato sauce, soy sauce, gravy granules, processed meats, pickles, ready meals and takeaways.
When it comes to processed foods, check labels carefully for salt or sodium – two loaves of bread or boxes of cereal made by the same company can contain wildly different quantities. “When buying tinned fish, pulses or vegetables, opt for the ones in water over brine,” says Kate Llewellyn-Waters, author, nutritionist and resident expert on TV programme You Are What You Eat. Know your high-salt items – ketchup, soy sauce, gravy granules, processed meats, pickles, ready meals and takeaways.
Opting for unsalted butter is one example of a simple swap you can make. The FoodSwitch app allows you to scan the barcodes of food and drink and instantly see whether they are high, medium or low in salt. It also suggests healthier alternative products.
“When cooking, one of the most effective tips to retrain your taste buds is to add herbs or spices in place of salt,” says Llewellyn-Waters. “Lemon juice, cumin, shallots and fresh or dried herbs will all add flavour.”
The good news is that salt preference is an acquired taste that can be unlearned. It takes six to eight weeks to adjust to much lower quantities – after that, you’ll never enjoy a pretzel again!
3. Foods that reduce blood pressure
“Potassium is an important mineral that helps your body get rid of sodium and reduces pressure on your blood vessels,” says Llewellyn-Waters. “Western diets tend to be high in sodium and low in potassium.” Foods that are rich in potassium include bananas, leafy greens, sweet potatoes, nuts (unsalted), seeds, tomatoes, avocados, apricots, and mushrooms. Opt to get your potassium from these rather than potassium supplements. For those with kidney disease or taking certain blood pressure medication, a large increase in potassium could be harmful, so check with your doctor before making big changes.
Potassium, found in foods like bananas, leafy greens, sweet potatoes, nuts (unsalted), seeds, tomatoes, and avocados, is an important mineral that helps your body get rid of sodium and reduces pressure on your blood vessels.
New research has found that eating bananas is more effective at lowering blood pressure than reducing salt intake in a fibre-rich diet. Another study tracked the fibre consumption of 200 people with hypertension and Type 2 diabetes. Their fibre intake was increased by about 25% to 38g a day and they consumed 1200-1500 calories. After six months, researchers observed a 15% reduction of systolic blood pressure. Another study tracked the fibre intake of more than 2500 midlife women and found that fibre – especially from grains – contributed to a lower risk of hypertension.
4. Exercise more
“Your heart is a muscle. Regular exercise makes it stronger and able to pump blood with less effort, which brings down blood pressure,” says Ruth Goss. “Aim for 150 minutes of moderate exercise a week.” One meta-analysis of 270 randomised controlled trials compared five different forms of exercise – aerobic, weight training, a combination of both, high-intensity interval training and isometric exercise. All improved blood pressure but isometric exercise – such as planks, squats and wall sits – had the most pronounced effect. “It’s normal for blood pressure to rise after exercise and it should come back down when you stop,” says Goss. “If your blood pressure is very high, speak to your GP or nurse before starting anything new.”
“If you’re overweight, losing some pounds will lower your blood pressure as your heart won’t need to work so hard to pump the blood around your body,” says MacGregor. If you’re overweight, even losing a moderate amount – 5 or 10% of your body weight – can make a difference. As a general guide, blood pressure can go down by about 1mmHg with each kilogram (about 2.2lb) of weight lost. Your waistline is important too – research shows that carrying excess weight around your stomach may increase your risk of high blood pressure more than anywhere else on your body.
Cutting down your alcohol intake can help reduce blood pressure. Photo / 123rf
6. Cut back on alcohol
“We know that drinking alcohol in excessive amounts raises blood pressure,” says MacGregor. “Your blood pressure is pulled up when you experience a hangover.” Until recently, moderate drinking wasn’t thought to be a risk factor, but newer data that spanned several decades and included 20,000 people has suggested that blood pressure increases in line with alcohol consumption, starting from as little as one glass of wine per day. Alcohol can also lead to weight gain – which raises blood pressure – and interfere with certain blood pressure medications. Still, it’s too early for a change in guidelines, though MacGregor advises those drinking above recommended levels to cut back.
7. Quit smoking – and vaping
Smoking certainly causes a temporary rise in blood pressure by activating the sympathetic nervous system (SNS), which controls the body’s response to danger and raises the heart rate and blood pressure. Researchers have also reported “worrisome changes” in blood pressure and heart rates after vaping. Although experts disagree over the long-term effects of these temporary spikes, there’s no doubt that smoking increases the build-up of fatty material in the arteries, reducing the space for blood flow. Quitting will significantly reduce your risk of stroke or heart disease.
8. Prioritise sleep
Blood pressure tends to lower by as much as 20% when we sleep – known as “nocturnal dipping”. There’s a whole body of literature that suggests that regular sleep deprivation – less than five hours a night – as well as interrupted sleep is associated with higher blood pressure, particularly in women during middle age. Worrying about this certainly won’t help you sleep better, but small steps to improve sleep hygiene – regular bedtime, daily exercise, no devices in bedrooms, blackout blinds – are worth taking.
Supplements that may help lower blood pressure include potassium, magnesium, vitamin D and fish oil, but it's important to check they won't interfere with any medication you're taking.
9. Know your supplements
“There are several supplements that may lower blood pressure, but it is vital to know that many supplements interact with medications, including blood pressure medication, so always check with your medical practitioner before taking any,” warns nutritionist Llewellyn-Waters. “Supplements that may help lower blood pressure include potassium, magnesium, vitamin D and fish oil.” One 2022 study found that a daily dose of around 2-3g of omega-3 fatty acids (found in salmon, tuna and other oily fish) may be the optimal amount needed to help lower blood pressure.
Garlic capsules have also shown effectiveness in reducing blood pressure, as well as improving cardiovascular health overall by reducing arterial stiffness, inflammation and elevated cholesterol levels.
10. Monitor your blood pressure at home
“Everyone should have a blood pressure monitor,” says MacGregor. “Many people have scales to help them control their weight – even though we can tell by sight or how our clothes fit if we’re overweight. We can’t tell when our blood pressure is raised – the first sign might be a heart attack. Getting a blood pressure monitor could be the best thing you’ve ever done.”
Monitoring at home will give you a more complete picture of day-to-day highs and lows, can motivate you to make changes and show you if those changes are working.
Buy a monitor approved by the British and Irish Hypertension Society for home use and follow the instructions carefully, keeping still and quiet while you take your reading, taking two or three, one or two minutes apart (see a full how-to below). Take the readings at the same time each day and always use the same arm, so you’re comparing like with like. Keep a record of your readings.
Systolic v diastolic
Blood pressure is measured in millimetres of mercury (mmHg). The top number is “systolic” – the pressure in your arteries when your heart beats. The bottom number is “diastolic” – the pressure in your arteries when your heart rests between beats. “Both are important, but for the over-50s, the top number is more important,” says MacGregor. “An elevated systolic pressure in the over-50s shows a greater risk of stroke and heart disease than an elevated diastolic pressure.”
What is hypertension?
Hypertension is another term for high blood pressure and the point where it could be treated with medication. That’s set at 140/90, although, says MacGregor, to some extent that’s an arbitrary cut-off point. “The risks from high blood pressure don’t stop at a particular number. If you’re below that threshold but it’s still raised, you need to do something about it.” Hypertension carries no symptoms but it’s a huge risk factor for stroke and cardiovascular disease, the world’s leading cause of death, as well as other conditions including kidney disease, vision loss and vascular dementia.
Blood pressure and age
“It goes up as we get older, so if you haven’t got high blood pressure now, you’re probably going to get it,” warns MacGregor. “In the UK, when you’re 20, your risk is roughly 20%, at 50, it’s 50%, at 80 years old, it’s 80%.” Diet is thought to be the critical cause here – age-related increases in blood pressure have been observed in almost every population except hunter-gatherers and forage farmers. In fact, salt is believed to be the culprit.
“When you eat salt, you retain some in your body, which controls the amount of fluid in your blood,” MacGregor explains. “Put simply, it’s like adding fluid to a central heating system – it raises the pressure. There have been studies on communities who have no access to salt at all. Their blood pressure doesn’t rise with age – their average blood pressure is 92/60 – the same as a gorilla or baboon.”
Garlic may help to increase a substance in your body known as nitric oxide, which can cause blood vessels to relax and dilate, thus decreasing blood pressure
The best salt substitutes to lower your intake
Garlic
“This has been used for centuries as both an ingredient and a medicine linked to numerous health benefits, including reduced blood pressure and decreased risk of heart disease,” says Kate Llewellyn-Waters, author and nutritionist.
“Garlic may help to increase a substance in your body known as nitric oxide, which can cause blood vessels to relax and dilate, thus decreasing blood pressure.”
Chilli pepper
“This will give your food a kick, which is down to capsaicin, the compound that makes chillies spicy. Chilli may also help maintain blood-vessel health,” she recommends.
Ginger
Llewellyn-Waters adds: “This is a great alternative to salt in your food as it has anti-inflammatory and antioxidant properties.”
Rosemary
“A beautiful, fragrant herb that is very high in antioxidants,” she says.
